Rotation of the Outer Layer of the Sun
Abstract
The problem of differential rotation in the radiative regions of slowly rotating mainsequence stars is addressed. Inhomogeneous compositions and magnetic fields are ignored. Although this is a classic problem in astrophysics, several fundamental questions regarding the basic magnitude and structure of the flow remain unanswered. Von Zeipel pioneered the study of this problem by showing that solidbody rotation is not possible in radiatively stable zones. The goal of this present work is to find alternatives to pure solid body rotation. A numerical approach was tried, but found to be too illconditioned to give accurate results. However, in setting up the equations for numerical solutions, we solved the longstanding computational problem of how to compute efficiently highorder solutions at a coordinate singularity. The classical derivation of the von Zeipel paradox is derived analytically to be incorrect for slowly rotating stars and a new proof is shown. This new derivation shows that solidbody rotation is allowed if certain conditions are fulfilled, and that those conditions are approximately fulfilled in the outer regions of the radiative zones of solarlike stars. A firstorder perturbation is used to compute the differential rotation.
 Publication:

Ph.D. Thesis
 Pub Date:
 1990
 Bibcode:
 1990PhDT........18B
 Keywords:

 STARS;
 RADIATIVE ZONES;
 SOLID BODY ROTATION;
 Engineering: Mechanical, Physics: Astronomy and Astrophysics, Mathematics;
 Main Sequence Stars;
 Radiative Transfer;
 Stellar Rotation;
 Sun;
 Astrophysics;
 Perturbation Theory;
 Solar Physics